Administering apparatus comprising a dosage display

ABSTRACT

An administering apparatus with a dosage display, including a casing, a reservoir for a fluid product, a driven device which acts on the product, a dosing means for selecting a product dosage to be delivered which includes a dosage scale including a number of dosage marks axially spaced from each other, and a drive device coupled to the driven device for driving the driven device, the drive device performing a delivery stroke from an initial position, in a drive direction, to a delivery stopper, the length of the delivery stroke counter to the drive direction being limited by selecting the product dosage using the dosing means, wherein the casing is transparent at least in an area overlapping the dosage scale, and wherein the drive device forms an indicator to the dosage scale in order to indicate the initial position of the drive device.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of German Patent Application No. 102 32410.7, filed on Jul. 17, 2002.

BACKGROUND

The invention relates to administering devices and methods. Moreparticularly, it relates to an administering apparatus or device with adosage display which allows a product dosage to be selected, and to amethod of providing a dosage display. The administering device of thepresent invention may be used in medical, veterinary, therapeutic,diagnostic, pharmaceutical and/or cosmetic applications. One preferredexample of administering apparatus in accordance with the presentinvention is injection apparatus, including injection pens. Otherexamples of administering apparatus according to the invention caninclude inhalation apparatus or apparatus for administering liquidnutrients in doses.

Administering apparatus which allow a dosage to be selected naturallyhave a dosage display in order to indicate the selected product dosageto be administered to the user of the apparatus. A reliable dosagedisplay is essential for selecting and administering the desired productdosage.

In the injection apparatus known from U.S. Pat. No. 6,628,067 B1, anoptical dosage display is provided between two casing sleeves which canbe rotated relative to each other, for selecting a dosage. The twocasing sleeves overlap each other. A dosage scale is printed onto theinner casing sleeve in the overlapping area, the scale consisting of asequence of dosage numbers representing dosage units. The outer casingsleeve in the overlapping area is transparent in the area of the dosagescale, by comprising an opening there which serves as a viewing window.To select a dosage, the two casing sleeves are rotated relative to eachother. The injection apparatus further comprises a dosing sleevearranged in the overlapping area between the two casing sleeves which isaxially moved relative to the casing sleeves, to select the dosage. Thedosing sleeve likewise comprises a viewing window for reading the dosagescale. The dosage scale is read through the two superimposed viewingwindows of the dosing sleeve and the outer casing sleeve.

The selected product dosage can indeed be reliably read with the aid ofthis dosage scale. However, the user then only knows that he hasselected the desired dosage. It remains uncertain whether the entiredosage or only a part of it, for example because evacuation of a productreservoir is already in progress, can be administered in the nextinjection.

SUMMARY

It is one object of the invention to provide a dosage display whichgives reliable information about a product dosage which can actually beadministered.

In one embodiment, the present invention comprises an administeringapparatus with a dosage display, including a casing, a reservoir for afluid product, a driven device which acts on the product, a dosing meansfor selecting a product dosage to be delivered comprising a dosage scalecomprising a number of dosage marks axially spaced from each other, anda drive device coupled to the driven device for driving the drivendevice, wherein the casing is transparent at least in an areaoverlapping the dosage scale, and wherein the drive device forms anindicator relative to the dosage scale to indicate the initial positionof the drive device.

The invention relates to a dosage display of an administering apparatus.In one embodiments, the administering apparatus comprises a casing whichaccommodates a reservoir for a fluid product or forms said reservoiritself. A product container which is accommodated in the casing, forexample, an ampoule, can form the reservoir. A conveying device of theadministering apparatus, mounted by the casing, comprises a drivendevice and a drive device which are coupled to each other in order todeliver product out of the reservoir, i.e., to convey product out of thereservoir through an outlet of the reservoir, to be administered. Thedriven device acts on the product, and is driven for this purpose by thedrive device.

The administering apparatus further comprises a dosing means, usingwhich a product dosage to be delivered can be selected. The drive devicecan be moved from an initial position in a drive direction up to adelivery stopper which is formed by the casing or can at least be fixedsuch that it cannot move relative to the casing with respect to thedrive direction. The length, measured in the drive direction, of thisdelivery stroke of the drive device is set by selecting the productdosage by means of the dosing means. The delivery stroke is preferably alinear translational movement, but can in principle also be performedalong a curved arc and can also be or comprise a rotational movement.

The dosing means comprises a dosage scale having a number of dosagemarks for optically displaying dosage units. Preferably, in oneembodiment, each product dosage, measured in dosage units, which can beselected is precisely allocated one dosage mark from the number ofdosage marks. The dosage marks are spaced out from each other in thedrive direction, such that each dosage mark from the number of dosagemarks assumes a different height with respect to the drive direction,preferably an axial line corresponding to the drive direction.

The casing is transparent, at least in an area which overlaps the dosagescale. When it is mentioned in this context that the transparent areaoverlaps the dosage scale, then “overlap” is intended merely to meanthat the dosage scale can be read in the transparent area of the casing.This can be achieved by providing the casing with an opening throughwhich the dosage scale can be entirely or only partially read. Morepreferably, however, in one embodiment, the casing itself is a supportfor the dosage scale in the transparent area, for example by printingthe dosage scale on an inner or outer surface of said area of the casingconsisting of transparent material or forming it in the transparentcasing material. Thus, the dosing scale can be produced in a transparentcasing material of suitable material composition by means of laserirradiation. It is sufficient for the purposes of the invention if thecasing is only transparent in the area overlapping the dosage scale. Thecasing may, however, also be completely transparent.

According to the invention, the drive device forms an indicator of thedosage scale whose axial position relative to the dosage scale can beread due to the transparency of the casing, in order to display thesited initial position of the drive device through the casing, relativeto the dosage marks spaced out in the drive direction. The dosage scaleis therefore a length scale extending in the drive direction, whoselength units are the dosage marks spaced out in the drive direction. Byreading, i.e., comparing, the position of the indicator of the drivedevice on this length scale, the user knows what delivery stroke thedrive device will perform when the drive device is moved from itsinitial position in the drive direction up to the delivery stopper.Precisely when the drive device assumes a front end position in which itabuts the delivery stopper, the indicator of the drive device assumesthe zero position on the dosage scale corresponding to a zero dosage.

In one preferred embodiment, the dosage marks spaced out in the drivedirection are bar marks, each of said dosage marks formed by preciselyone bar mark which extends over a particular length perpendicular to thedrive direction and is advantageously as fine as possible. The indicatorformed by the drive device is preferably also a bar or comprises a barwhich points parallel to the bar marks. In principle, the indicator ofthe drive device can also be arrow-shaped or can exhibit a differentshape suitable for an indicator, said shape enabling the position of thedrive device on the dosage scale as compared to the dosage marks to bereliably identified.

In one preferred embodiment, the dosage scale additionally comprisesdosage symbols which each represent a particular dosage, each of thesymbols representing a different dosage. These dosage symbols, which arepreferably dosage numbers corresponding directly to the dosage units,can also simultaneously form the spaced out dosage marks, by beingappropriately shaped. Preferably, however, the dosage marks inaccordance with the invention are provided in addition to such dosagesymbols. In one embodiment, each of the dosage marks is allocated adosage symbol in its immediate vicinity, such that the user can not onlyread the exact position of the display device, measured in the drivedirection, on the dosage scale, but simultaneously also the dosagecorresponding to this position, symbolically or directly in the form ofa dosage number.

In one embodiment, the dosing means also comprises a dosage scale foroptically displaying the product dosage selected. In one embodiment, thedosage scale on which the position of the drive device can be read alsosimultaneously forms the dosage scale for displaying the product dosageselected. In principle, however, it would also be conceivable to providea separate dosage scale for each of these two dosage displays. Incombination, the two integrated or independent dosage displays provide adisplay of the remaining amount. If, namely, a product dosage isselected which exceeds a remaining dosage still available in thereservoir, then comparing the dosage displays provides the user with areliable indication that the selected product dosage can no longeractually be delivered or has not actually been delivered. Which of thesetwo pieces of information the user receives depends on the type ofcoupling between the driven device and the drive device. In one case,the drive device cannot be moved up to the delivery stopper, such thatthe dosage display in accordance with the invention displays this stateafter administering. In one preferred embodiment, the drive device canonly be moved relative to the driven device, opposite or counter to thedrive direction, by a path length which corresponds to the remainingdosage still left in the reservoir. In this case, the user can directlyread the remaining dosage left before delivery and, by comparing it withthe display of the product dosage selected, determine the missingdosage. In this preferred variant of the coupling between the drivendevice and the drive device, the driven device forms a reverse stopper,which is the maximum to which the drive device can be moved counter tothe drive direction, relative to the driven device.

For selecting the product dosage, the dosing means comprises a dosingmember which forms the dosing stopper for the drive device. In oneembodiment, the drive device can be moved counter to the drive directionup to said dosing stopper. A slight distance between the deliverystopper and the dosing stopper, as viewed in the drive direction,corresponds to the delivery stroke of the drive device, wherein howevera deduction is to be made for the formation of a front and a rearstopper area of the drive device, measured in the drive direction.

The dosage scale for displaying the product dosage selected can beconnected to the dosing member. In one preferred embodiment, however, itis connected to the casing, in particular when the same dosage scalealso forms the display for the position of the drive device. If thedosage scale is connected to the casing, the dosing member forms anindicator whose position relative to said dosage scale indicates theproduct dosage selected. The indicator of the dosing member is formed bya viewing window, which may, in one embodiment, be developed into amagnifier.

Operational comfort is accommodated if the product dosage selected andthe position of the drive device measured in the drive direction can beread in one glance, i.e., simultaneously. Expediently, the position ofthe drive device and the product dosage selected can be read alongsideeach other in the drive direction, providing the position of the drivedevice does not already exactly correspond to the product dosageselected. In one embodiment, if the product dosage selected is deliveredfrom the initial position of the drive device by the delivery stroke,the indicator of the drive device and the indicator for displaying theproduct dosage selected overlap.

In one preferred embodiment, the dosing member can be movedtranslationally in the drive direction and/or counter to the drivedirection, to adjust the dosing stopper. Its dosing movement is acombination of the translational movement and a rotational movementabout the translational axis. In principle, however, the dosing movementof the dosing member could also be a purely translational or purelyrotational movement. For one preferred embodiment of the combinedrotational and translational movement, the dosing member is coupled tothe casing via a swivel joint, preferably a screw joint, such that therotational movement of the dosing member causes its translationalmovement.

If the dosing movement of the dosing member is a combined rotational andtranslational movement, wherein the rotational axis corresponds to thetranslational axis, then the dosage scale for displaying the productdosage selected is advantageously a sequence of dosage symbols, e.g.,dosage numbers, running spirally around the rotational axis. As alreadyexplained, the same dosage scale can also form the dosage scale fordisplaying the position of the drive device, by allocating its dosagemarks to the dosage symbols or by realizing them using the dosagesymbols themselves, by appropriately representing them. In oneembodiment, it is particularly advantageous if the indicator of thedrive device extends circumferentially around the rotational axis of thedosing member, for example as a fine, intermittent or preferablycontinuous line, such that the indicator of the drive device can be readon the dosage scale in any rotational angular position of the dosingmember.

In one preferred embodiment, the dosing member comprises an inner dosingbody and an outer dosing body, between which a slight gap remains in anoverlapping area. The inner dosing body protrudes into the casing. Thecasing protrudes into the slight gap. The outer dosing body can inparticular form a gripping part of the dosing member. The dosing bodiesare preferably arranged such that the dosing member can be rotatedrelative to the casing engaging with the gap. The nested arrangement ofan inner dosing body and an outer dosing body allows the dosing memberto be designed axially short. By producing the two dosing bodiesseparately, the dosing member can be more simply equipped than in thecase of producing them as one piece having a higher functionality. Ifproduced separately, the inner dosing body and the outer dosing body maybe suitably connected to each other such that a translational movementbetween the dosing bodies along a translational axis and a rotationalmovement about the translational axis are not possible, but rather onedosing body slaves the other.

In one embodiment, the driven device preferably comprises a piston whichis accommodated in the reservoir such that it can axially move in anadvancing direction towards an outlet of the reservoir, in order todeliver product from the reservoir. In this embodiment, the drivendevice also comprises a piston rod. The driven device directly engageswith the piston rod. The piston rod can be formed together with thepiston as one piece or can be fixedly connected to the piston, forexample by means of a screw connection or a fixed plug connection. Inone preferred embodiment, however, the piston rod is formed as aseparate part from the piston, said part pressing against the piston todeliver the product in the advancing direction. If the product isconveyed by means of a piston, then the advancing direction of thepiston and the drive direction correspond.

In one embodiment, the driven device is coupled to the piston rod suchthat it slaves the piston rod when moved in the drive direction, butperforms a movement counter to the drive direction without the pistonrod. The piston rod and the driven device can be coupled via one or moretransfer members. In one preferred embodiment, the piston rod and thedriven device directly engage, causing the piston rod to be slaved. Theengagement is releasable, in order to enable the reverse movement of thedrive device, relative to the piston rod.

The piston rod can be mounted by the casing such that it can axiallymove back and forth. In this case, the product dosage to be delivered isset by adjusting an axially slight distance between a front end of thepiston rod and the rear side of the piston by selecting the product. Inthis case, the piston rod forms the indicator of the drive device.

In some preferred embodiments, the piston rod is mounted by the casingsuch that it can be moved in the advancing direction but not counter tothe advancing direction. In this case, movement counter to the advancingdirection is at best possible in the course of exchanging the reservoirusing corresponding assembly handles. In some preferred embodiments,however, restoring the piston rod is not possible. Rather, theadministering apparatus is completely replaced by a new one. It wouldalso be conceivable to divide the apparatus into a reservoir moduledesigned as a disposable module and a dosing and drive module which canbe repeatedly used with new reservoir modules. This design has alreadybeen successfully pursued in injection apparatus in the form ofso-called semi-disposable injection pens and can also be advantageouslyused for the administering apparatus of the invention.

The fluid product to be administered or delivered may be a liquid formedical, therapeutic, diagnostic, pharmaceutical or cosmeticapplications, or in combination for a number of these applications. Theproduct can, for example, be insulin, a growth hormone, cortisone,collages or also liquid nutrients. In some embodiments, theadministering apparatus is preferably used in applications in which auser administers the product himself/herself, as is usual in diabetestherapy. Application by trained staff only or also in the ward oroutpatients field should not, however, be ruled out.

In the case of an injection apparatus, the product can be administeredby suitable means, for example an injection cannula or a nozzle forneedle-free injections. The injection can be subcutaneous, venous orintramuscular. In some embodiments, the administering apparatus can bean inhalation apparatus in which the product dosage selected or aremaining dosage still available in the reservoir is delivered from thereservoir, for example, into a chamber of the inhalation apparatus, andatomized by means of a vaporizer or other atomizing means, forinhalation. Furthermore, taking the product orally or administering theproduct via a feeding tube is also conceivable, to name but a fewexamples of administering.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an injection apparatus in a longitudinal section;

FIG. 2 depicts the rear part of the injection apparatus;

FIG. 3 depicts the injection apparatus in a cross-section;

FIG. 4 depicts a dosing member of the injection apparatus in alongitudinal section;

FIG. 5 depicts a modified dosing member in a longitudinal section;

FIG. 6 depicts the rear part of the injection apparatus in aminimum-dosage state and “not loaded”;

FIG. 7 depicts the rear part of the injection apparatus in amaximum-dosage state and “not loaded”;

FIG. 8 depicts the rear part of the injection apparatus in amaximum-dosage state and “loaded”;

FIG. 9 depicts a view onto a dosage display in the apparatus state inFIG. 6;

FIG. 10 depicts the view onto a dosage display after a “loading process”from the state in FIG. 9;

FIG. 11 depicts the view onto a dosage display in the apparatus state inFIG. 7;

FIG. 12 depicts the view onto a dosage display in the apparatus state inFIG. 8; and

FIG. 13 depicts a dosage scale, unwound onto the plane of the page.

DETAILED DESCRIPTION

FIG. 1 shows a complete longitudinal section of an injection apparatus.It is a gear rack pen for self-administering, for example, insulin orgrowth hormones. A first, front casing section 1 and a second, rearcasing section 3 form a casing of the pen. The casing sections 1 and 3are sleeve bodies. To form the casing, they are plugged into each otheralong a common central longitudinal axis L, in a non-releasableconnection. Furthermore, the connection is such that the casing sections1 and 3 cannot be moved relative to each other, either axially orrotationally about the longitudinal axis L.

An ampoule 2 accommodated in the front casing section 1 forms areservoir for a product which is administered by way of injection usingthe pen. An outlet of the ampoule 2 is sealed by a membrane. Aninjection needle N is however guided through the membrane and protrudesvia a rear end into the ampoule 2. A piston K is accommodated at a rearend of the ampoule 2 facing away from the outlet. An axial movement ofthe piston K along the longitudinal axis L in an advancing directionpointing towards the ampoule outlet delivers product from the ampoule 2and through the injection needle N, thus administering it. In the stateshown, the front casing section 1 is covered by an outer protective capP and the injection needle N, still separate, is covered by an innerprotective cap which of course has to be removed before administering.

The rear casing section 3 forms a mechanism holder by mounting a pistonrod 8 acting on the piston K in the advancing direction and the othercomponents of the pen, which participate in selecting a product dosageto be delivered and delivering the product dosage selected. These othercomponents are a drive member 10 and an operating element 18 whichtogether form a drive device 37 for the piston rod 8, and furthermore adosing member 35 which in cooperation with the rear casing section 3serves to select the product dosage to be delivered from the ampoule 2.

In FIG. 2, these components and their couplings are shown enlarged.Reference may also always be additionally made to the cross-sectionalrepresentation in FIG. 3. On the outer surface of the piston rod 8, fourrows of teeth 9 formed from serrated teeth extend in the longitudinaldirection, each offset by 90° with respect to each other. The rows ofteeth 9 each exhibit the same separation. Each of the rows of teeth 9 isoffset by a quarter pitch with respect to each of the other rows ofteeth 9, in order to improve the dosing precision in a way known in itsown right.

The rear casing section 3 forms blocking elements 4 which engage withthe rows of teeth 9. The piston rod 8 is blocked by the engagement ofthe blocking elements 4, such that it is not possible to move the pistonrod 8 counter to the advancing direction of the piston K. Movement ofthe piston rod 8 in the advancing direction, however, is permitted.

In order to advance the piston rod 8, the drive device 37 engages withthe rows of teeth 9 of the piston rod 8 via slaving means 11, behind theblocking elements 4. The drive device 37 is formed by the sleeve-shapeddrive member 10 and the sleeved-shaped operating element 18. Theoperating element 18 is pushed from behind onto the drive member 10. Theconnection between the drive member 10 and the operating element 18 issuch that the operating element 18 cannot be axially moved relative tothe drive member 10, but can be rotated about the longitudinal axis Lrelative to the drive member 10. The longitudinal axis L forms atranslational axis of the drive device 37 and the driven device K, 8consisting of the piston K and the piston rod 8, and furthermore, arotational axis of the operating element 8.

The drive device 37 viewed as a whole protrudes through the dosingmember 35. The slaving means 11 of the drive member 10 can be bent free,in particular free from the dosing member 35, elastically outwards fromthe mesh, in the radial direction, in order to enable the drive device37 to move relative to the piston rod 8 counter to the advancingdirection. The slaving means 11 are formed in a section of the drivedevice 37 protruding forwards out of the dosing member 35; in theexample embodiment, they form the front end of the drive device 37. Theengagement of the slaving means 11 and the shape of the rows of teeth 9are such that the piston rod 8 is necessarily slaved by a movement ofthe drive device 37 in a drive direction directed towards the piston K,said drive direction being identical to the advancing direction.

In the depicts exemplary embodiment, the rows of teeth 9 are pointed inthe advancing direction in a shape of serrated teeth. In modifiedembodiments, however, the piston rod 8 could comprise, instead of one ormore rows of teeth 9, recesses or other engaging means for slaving meansof a drive device, if it is only ensured that piston rod 8 isnecessarily slaved in the advancing direction but is prevented frombeing slaved counter to the advancing direction.

The dosing member 35 is formed by a sleeve-shaped inner dosing body 13and a sleeve-shaped outer dosing body 14, which are produced as separateparts and immovably connected to each other. In particular, it is notpossible for the two dosing bodies 13 and 14 to either axially move orrotate about the longitudinal axis L relative to each other. The outerdosing body 14 concentrically surrounds the inner dosing body 13. Aslight annular gap, into which the likewise sleeve-shaped rear casingsection 3 protrudes, remains circumferential between the two dosingbodies 13 and 14.

The rear casing section 3, together with the dosing body 35, forms aswivel joint, more precisely a screw joint, which causes a rotationalmovement of the dosing member 35 about the longitudinal axis L to resultin a translational movement of the dosing member 35 in or counter to theadvancing direction, i.e., a axial translational movement relative tothe rear casing section 3, depending on the direction of rotation. Thelongitudinal axis L forms a rotational axis and a translational axis ofthe dosing member 35. To form the swivel joint, the rear casing section3 and the dosing member 35 are in threaded engagement. The threadedengagement is between an inner thread 6 formed on an inner surface areaof the rear casing section 3 and an outer thread 16 formed on an outersurface area of the inner dosing body 13. Although less preferred, thethreaded engagement could instead also be formed between an outer threadof the rear casing section 3 and an engaging inner thread of the outerdosing body 13. By rotating the dosing body 35, the user selects theproduct dosage to be administered. Since, through the threadedengagement, the dosing member 35 also simultaneously performs an axialtranslational movement, a delivery stroke of the length Ah is set forthe drive device 37, which corresponds to the product dosage selected.

The inner dosing body 13 forms a dosing stopper 15 which limits themovement of the drive device 37 counter to the advancing direction. Moreprecisely, a facing area of the dosing stopper 15 pointing in theadvancing direction forms the dosing stopper 15 at its front end. Thedosing stopper 15 is formed by an annular collar running around thelongitudinal axis L, said collar protruding radially inwards towards thedrive member 10 via an inner surface area of the inner dosing body 13.The dosing stopper 15, more precisely its front stopper area, runsaround the longitudinal axis L at an axially constant height, i.e. alinear dosing stopper 15 is formed at a single height.

Opposite the dosing stopper 15 in the advancing direction, the rearcasing section 3 forms a delivery stopper 5 which limits the movement ofthe drive device 37 in the advancing direction. The drive device 37 canthus be moved in and counter to the advancing direction between thedelivery stopper 5, which is fixed to the casing and even formed by therear casing section 3 itself, and the translationally adjustable dosingstopper 15. The drive device 37 in turn forms a counter stopper, namelythe delivery and dosing stopper 12, on an outer surface area of thedrive member 10. The delivery and dosing stopper 12 is formed by anannular collar via a front stopper area facing the delivery stopper 5and a rear stopper area facing the dosing stopper 15. The delivery anddosing stopper 12 protrudes radially outwards from an outer surface areaof the drive member 10 towards a facing inner surface area of the rearcasing section 3.

The rear casing section 3 is completely transparent or at leasttransparent in the section which overlaps a maximum delivery stroke ofthe drive device 37. The transparency serves to verify the axialposition of the drive device 37, in particular the position of the drivemember 10 which engages directly with the piston rod 8 and is rigidlyconnected to it via the engagement in the advancing direction.

For the purpose of a particularly precise optical verification, thedrive member 10 is provided with a thin marking line, preferably acircumferential marking line, which is clearly visible through the rearcasing section 3 and forms an indicator 32 (FIGS. 9 to 11).Advantageously, the delivery and dosing stopper 12 itself can form themarking line by forming a thin tip, radially outwards. The delivery anddosing stopper 12 is suitable as an indicator for verifying, alonebecause it radially protrudes almost directly up to the rear casingsection 3 or even contacts it with sliding contact. The radially outersurface area of the delivery and dosing stopper 12 or the entire,radially outer tip is preferably additionally provided with a thinmarking line which is attached on the surface or in a recess on thesurface or is formed in the material, and can advantageously befluorescent.

As may be seen in connection with FIGS. 9 to 12, and in particular inFIG. 13, the rear casing section 3 comprises a dosage scale 30 over thelength of a maximum delivery stroke Ahmax. The dosage scale 30 can beattached to the inner surface area or more preferably to the outersurface area of the rear casing section 3 or let into the transparentsurface of the rear casing section 3. In the example embodiment, it isattached to the outer surface area. The dosage scale 30 is formed bydosage numbers which indicate dosage units and by dosage marks 31. Eachof the dosage numbers is each assigned to one of the dosage marks 31.The dosage marks 31 are formed by short, thin lines which each extend inthe circumferential direction of the rear casing section 3. The dosagenumbers are arranged over the circumference of the casing section 3,ascending towards the rear, in the form of spiral around the rotationalaxis L of the dosing member 35. Correspondingly, the dosage marks 31 arespirally arranged, such that each of the dosage marks 31 exhibits adifferent axial height to each of the other dosage marks 31. The dosagemarks 31 thus represent, in a fine axial grading, every product dosagewhich can be selected and delivered in whole dosage units. Due to thetransparency of the rear casing section 3, the axial position of thedrive device 37 can be read, namely as the axial position which theindicator 32 of the drive device 37 assumes relative to the dosage marks31. In the example embodiment, the cited marking line running around thelongitudinal axis L on the radially outer tip of the delivery and dosingstopper 12 forms the indicator 32 of the drive device 37.

In order to make it easier to read the dosage scale 30, in particularfor people with low visual acuity, the outer dosing body 14 comprises aviewing window 34 in a surface section which overlaps the dosage scale30, said viewing window being developed into a magnifier 34 a. Theviewing window 34 is sufficiently large and of such a shape thatprecisely one of the dosage numbers of the dosage scale 30 can beidentified as the dosage selected, through the viewing window 34. In theexample embodiment, it is only ever possible to read exactly one dosagenumber through the viewing window.

In order that the dosage can be selected in discrete steps correspondingto the dosage numbers of the dosage scale 30, the dosing member 35 andthe rear casing section 3 are each in releasable latching engagement indiscrete rotational angular positions which the dosing member 35 canassume relative to the rear casing section 3. The latching engagement isformed between axially extending grooves 7 and engaging members 17 whichengage with the grooves 7. In the example embodiment, the axial grooves7 are let into the rear casing section 3 on the outer surface area. Theengaging members 17 are correspondingly formed as short latching cams onthe inner facing surface area of the outer dosing body 14. The engagingmembers 17 are linearly guided axially in the axial grooves 7 in each ofthe discrete rotational angular positions of the dosing member 35.

A rear end position of the dosing member 35 is defined by the engagingmembers 17 abutting a rear facing limiting area of the axial grooves 7.A front end position of the dosing member 35 is defined by a rearconnecting stay, which the dosing bodies 13 and 14 form betweenthemselves, abutting against a rear facing area of the rear casingsection 3. The dosing member 35 can be adjusted back and forth, fromrotational angular latching position to rotational angular latchingposition, between these two extreme dosing positions, in order toaxially adjust the dosing stopper 15. The maximum delivery stroke Ahmaxof the drive device 37 is as large as the axial distance which thedosing stopper 15 exhibits from the delivery stopper 5 in the rear endposition of the dosing member 35 minus the axial thickness of thedelivery and dosing stopper 12.

Although the user can at any time freely alter the product dosage setbetween the two extreme dosing positions, it is advantageous for mostapplications if a dosage, once set, no longer has to be altered. Theinjection apparatus can therefore be flexibly set to the needs ofdifferent users on the one hand, and used with an optimal setting for aparticular user for repeatedly administering the same product dosage. Inthis sense, a dosage memory is also simultaneously obtained through thedosing member 35 which can be rotationally and translationally moved andtherefore adjusted in combination, relative to the rear casing section3.

One advantage which should by no means be neglected is that thedimensional accuracy and simply regulation of the dimensional accuracyand the stable design of the components which are decisive for dosingand delivery are realized using very few components. This contributes tothe fact that the apparatus has a simply design and not least istherefore cheap, but nonetheless operates with precision and ensuresexact dosing.

The nested arrangement of the dosing bodies 13 and 14 is alsoadvantageous, providing multi-functionality of the dosing member 35despite its simple construction. For the dosing member 35 directly formsthe dosing engagement with the casing of the injection apparatus, thedosing stopper 15 for the drive device 37, a gripping part for the userand a part of a duplex dosage display, namely the display for the dosageselected on the one hand and the display for the dosage delivered on theother.

As a further advantage, the injection apparatus enables simple andreliable priming, i.e., bleeding the product-guiding parts between thepiston K and the exit opening of the injection needle N.

To illustrate the priming function, reference is made to FIGS. 1 and 2and in particular also to FIGS. 3, 4 and 5. In order to fulfill thepriming function, the inner dosing body 13 and the operating element 18are engaged. The engagement consists of a guiding curve and an engagingmember which engages with the guiding curve. The engaging member can bemoved in a defined manner in the guiding curve between axial stoppers onthe one hand and radial stoppers on the other. The guiding curve on theone hand and the engaging member on the other are formed on the mutuallyfacing surface areas of the inner dosing body 13 and the operatingelement 18.

As shown in FIGS. 3 and 4, the engaging member indicated as 19 is formedon an outer surface area of the operating element 18, while the guidingcurve indicated as 20 is let into the facing inner surface area of theinner dosing body 13. The guiding curve 20 comprises a long axialsection 21 and a contrastively short axial section 22 and a connectingsection 24 which extends in the circumferential direction and connectsthe two axial sections 21 and 22 to each other, at their rear ends. Thetwo side walls of the axial sections 21 and 22, which oppose each otherin the circumferential direction in the area of the connecting section24, form rotational stoppers 25 and 26 for the engaging member 19. Thelong axial section 21 extends in the advancing direction up to thedosing stopper 15, more precisely up to the rear facing area of theannular collar forming the dosing stopper 15. The shorter axial section22 runs parallel to the axial section 21 and is formed as a short blindgroove. A front facing area of the axial section 22 forms a primingstopper 23. The axial sections 21 and 22 feed onto the rear facing endof the inner dosing body 13. The connecting section 24 iscorrespondingly open at the rear facing end. The engaging member 19 isformed by an axial rib formed on the outer surface of the operatingelement 18. This axial rib forms the priming stopper on its free frontfacing area.

Because the engaging member 19 engages with the guiding curve 20 formedin this way, the operating element 18 can perform the shape of themovement corresponding to the guiding curve 20, relative to the innerdosing body 13, namely any selected delivery stroke Ah up to the maximumdelivery stroke Ah_(max), the contrastively smaller priming stroke Phand the rotational selecting movement. Since the operating element 18 isconnected to the drive member 10 such that it cannot move axially butcan rotate about the longitudinal axis L, the operating element 18 canbe rotated back and forth between the rotational stoppers 25 and 26without acting on the drive member 10. Axial translational movement ineither the long axial section 21 or the short axial section 22 is thenonly possible, however, together with the drive member 10.

Because the connecting section 24 is arranged on the rear ends of theaxial sections 21 and 22, the rotational movement of the operatingelement 18 between the two rotational stoppers 25 and 26, i.e., from thedelivery position to the priming position and vice versa, is onlypossible when the drive member 10 is abutting the dosing stopper 15 viaits delivery and dosing stopper 12. In this “loaded” position, theengaging member 19 can be moved by rotating the operating element 18relative to the inner dosing body 13 against the rotational stopper 25and thus into axial flush with the priming stopper 23. In thisrotational angular position of the operating element 18, the primingposition, the drive device 37 can be moved in the advancing direction byaxially pressing onto the operating element 18 up to the priming stopper23. The axial length Ph of this priming stroke is only a few dosingunits, for example two, three or four dosing units. The axial distancebetween the priming stopper 23 and the priming counter stopper whichforms the engaging member 19 is correspondingly short.

It is advantageous if the operating element 18 is in releasable latchingengagement with the inner dosing body 13 flush with the axial sections21 and 22, i.e., on the rotational stoppers 25 and 26, respectively. Inorder to obtain the latching engagement with the inner dosing body 13 ineach of the delivery position and the priming position, the engagingmember 19 is again provided with a thin, axial latching cam on itsnarrow outer surface area, said cam coming to rest in the two rotationalstopper positions of the operating element 18 in each of two axiallatching grooves formed correspondingly in the guiding curve 20.

In the exemplary embodiment, two identical guiding curves 20 andengaging members 19 are provided which diametrically oppose each other.

In the variant of FIG. 4, the connecting section 24 runs, simplylinearly, at a single axial height.

FIG. 5 shows a guiding curve 20 with a connecting section 24′ whosefront guiding wall leads from the priming stopper 23 obliquely backwardsinto the long axial section 21. Due to the oblique trajectory of theconnecting section 24′, a translational movement of the operatingelement 18—and together with it of the drive member 10—counter to theadvancing direction and relative to the piston rod 8 is caused by areverse rotational movement of the operating element 18 from therotational stopper 25 towards the rotational stopper 26. In accordancewith the embodiment of a priming process, the user therefore does nothave to specially retract the drive device 37 again relative to thepiston rod 8, i.e. load it. Rather, the winding or loading movement isforced by the reverse rotational movement. The guiding curve 20 in FIG.5 otherwise corresponds to the guiding curve 20 in FIG. 4.

The functionality of an embodiment of an injection apparatus inaccordance with the present invention will now be described. FIGS. 6 and9 show the rear part of the injection apparatus in a longitudinalsection, and each in a view in a state from which the dosage can beselected. Correspondingly, the drive device 37 abuts the deliverystopper 5, and the dosing member 35 assumes its axially front endposition. A slight distance remains between the delivery and dosingstopper 12 of the drive device 37 and the dosing stopper 15 of thedosing member 35, said distance corresponding to two dosing units.Accordingly, the dosage of two dosage units can be read in the viewingwindow 34. Furthermore, the dosage mark 31 assigned to this dosage canalso clearly be seen. Since the drive device 37 abuts the deliverystopper 5 via its delivery and dosing stopper 12, the marking line ofthe drive device 37 forming the indicator runs parallel to the dosagemark 31, with an axial distance. The distance corresponds to two dosageunits. This situation can be seen in FIG. 9. The injection apparatus is“loaded” by retracting the drive device 37, relative to the piston rod8, up to the dosing stopper 15. When this loading movement has beenperformed, two dosing units can be delivered by then advancing the drivedevice 37 and the thereby slaved piston rod 8. FIG. 10 shows this state,in which the drive device 37 abuts the dosing stopper 15 via itsdelivery and dosing stopper 12. The dosing mark 31 assigned to thedosage number “2” and the indicator overlap each other exactly.

From the state shown in FIGS. 6 and 9, the user selects the dosage. Toselect the dosage, the dosing member 35 has merely to be rotated aboutthe longitudinal axis L relative to the rear casing section 3. Here, theouter dosing body 14 forms a gripping part and the inner dosing body 13forms a dosing screw whose rotational movement is directly convertedinto the axial adjusting movement by the threaded engagement, for thepurpose of selecting the dosage. The dosing is in discrete rotationalangular positions which the dosing member 35 successively assumesrelative to the rear casing section 3.

FIGS. 7 and 11 show the injection apparatus directly after the dosagehas been selected. A dosage of 42 dosage units has been set, as can beread in the viewing window in FIG. 11. In the state shown in FIG. 7,selecting the dosage has been concluded but the injection apparatus isnot yet “loaded”, for the drive device 37 is still abutting the dosingstopper 5. This is indicated on the dosage scale 30 by the indicator 32,as can be seen in FIG. 11.

FIG. 8 shows maximum dosing. FIG. 12 shows the injection apparatus in astate in which selecting the dosage has been concluded but the drivedevice 37 has not been retracted by the thus defined delivery stroke oflength Ah, but rather only by a part of this stroke. In the state shownby way of example in FIG. 12, the drive device 37 has been retracted bya stroke corresponding to a product dosage of eight dosage units. Thisis indicated in FIG. 12 by the axial position of the indicator 32 on thedosage scale 30.

As illustrated in FIG. 12, a simple but reliable display of theremaining amount is obtained through the transparency of the rear casingsection 3, the form of the indicator 32 and the arrangement of thedosage scale 30. If, namely, the ampoule no longer contains the fullproduct dosage of, for example, 42 dosage units before the drive device37 is retracted, then the drive device 37 can only be retracted counterto the advancing direction until the length of its next delivery strokein the advancing direction corresponds to the product dosage stillavailable in the ampoule 2 for a final delivery. In the exemplaryembodiment, this remaining amount is eight dosage units. The indicator32 and the dosage mark 31 assigned to the dosage of eight dosage unitscorrespondingly overlap each other. The remaining amount which can bedelivered is defined by a stopper acting between the piston rod 8 andthe drive device 37. This stopper limits the effective length of thepiston rod 8, i.e. the length by which the piston rod 8 can be moved asa whole in the advancing direction, from its position before a firstdelivery up until the ampoule 2 is evacuated. In the exemplaryembodiment, the piston rod 8 forms this stopper for the slaving means 11in its rear part, i.e., the slaving means 11 cannot elastically evadethis stopper.

In the foregoing description, embodiments of the invention, includingpreferred embodiments, have been presented for the purpose ofillustration and description. They are not intended to be exhaustive orto limit the invention to the precise form disclosed. Obviousmodifications or variations are possible in light of the aboveteachings. The embodiments were chosen and described to provide the bestillustration of the principals of the invention and its practicalapplication, and to enable one of ordinary skill in the art to utilizethe invention in various embodiments and with various modifications asare suited to the particular use contemplated. All such modificationsand variations are within the scope of the invention as determined bythe appended claims when interpreted in accordance with the breadth theyare fairly, legally, and equitably entitled.

1. An administering apparatus with a dosage display, comprising: a) acasing comprising a reservoir for a fluid product; b) a driven devicewhich acts on said product contained in said reservoir, in order todeliver product; c) a dosing means, using which a product dosage to bedelivered can be selected, and which comprises a dosage scale with anumber of dosage marks axially spaced out from each other; and d) adrive device coupled to said driven device for driving the drivendevice, said drive device performing a delivery stroke from an initialposition, in a drive direction, up to a delivery stopper, the length ofsaid delivery stroke counter to the drive direction being limited byselecting the product dosage by means of said dosing means; e) whereinsaid casing is transparent, at least in an area overlapping said dosagescale; and wherein f) the drive device forms an indicator of the dosagescale, in order to indicate the initial position of the drive device inthe transparent area of the casing, relative to said dosage marks. 2.The administering apparatus as set forth in claim 1, wherein the dosingmeans comprises another indicator, in order to display the productdosage selected on the dosage scale or on another dosage scale.
 3. Theadministering apparatus as set forth in claim 2, wherein said indicatorof the drive device and said other indicator overlap in the initialposition of the drive device, if the drive device can perform themaximum stroke, set by selecting the product dosage, from the initialposition.
 4. The administering apparatus as set forth in claim 1,wherein the dosing means comprises a dosing member which performs adosing movement relative to the casing, in order to select the productdosage to be delivered, and wherein the position of said dosing memberis displayed on the dosage scale or on another dosage scale.
 5. Theadministering apparatus as set forth in claim 4, wherein the dosingmember is coupled to the casing such that it can be rotated about arotational axis pointing in the drive direction.
 6. The administeringapparatus as set forth in claim 4, wherein the dosing member and thecasing are coupled via a swivel joint, such that a rotational movementof the dosing member about a rotational axis pointing in the drivedirection causes an axial translational movement of the dosing member.7. The administering apparatus as set forth in claim 1, wherein thedosing means comprises a dosing member comprising an inner dosing bodyand an outer dosing body, between which a gap is formed into which thecasing protrudes, wherein said inner dosing body forms a dosing stopperfor selecting the product dosage, wherein said dosing stopper can beadjusted in or counter to the drive direction by operating said outerdosing body.
 8. The administering apparatus as set forth in claim 1,wherein the dosing means comprises a dosing member which forms a dosingstopper, can be moved counter to the drive direction up to the drivedevice, and is movably coupled to the casing, in order to select theproduct dosage by adjusting said dosing stopper relative to the casing.9. The administering apparatus as set forth in claim 1, wherein: thedriven device comprises a piston and a piston rod acting on said pistonin the drive direction, in order to deliver product from the reservoirby axially moving the piston in the drive direction; the drive devicecan be moved counter to the drive direction up to an adjustable dosingstopper; and the piston rod is prevented from moving counter to thedrive direction and is coupled to the drive device such that it isslaved by the drive device in the drive direction.
 10. The administeringapparatus as set forth in claim 1, wherein the dosage marks are alsospaced out from each other in the circumferential direction, around anaxis pointing in the drive direction.
 11. The administering apparatus asset forth in claim 1, wherein the casing is a support for the dosagescale for displaying the initial position of the drive device.
 12. Theadministering apparatus as set forth in claim 1, wherein the dosingmeans comprises a dosing member which performs a dosing movementrelative to the casing, in order to select the product dosage to bedelivered, and forms another indicator which displays the product dosageselected on the dosage scale or another dosage scale.
 13. Theadministering apparatus as set forth in claim 1, wherein the dosagescale serving to display the initial position of the drive devicecomprises a clearly assigned dosage symbol for at least a part of thedosage marks, said dosage symbol representing a product dosagecorresponding to the assigned dosage mark.
 14. The administeringapparatus as set forth in claim 1, wherein the drive device comprises amarking line on an outer surface area facing the casing, said markingline extending perpendicular to the drive direction and forming theindicator of the drive device.
 15. The administering apparatus as setforth in claim 1, wherein the dosage marks are formed by lines whichextend perpendicular to the drive direction.
 16. The administeringapparatus as set forth in claim 1, wherein said administering apparatusis an injection apparatus comprising an injection cannula of at most 30gauge, or an injection cannula having an outer diameter of at most 320μm and an inner diameter not specified in ISO 9626, wherein the wallthickness is thinner than is specified in ISO
 9626. 17. Theadministering apparatus as set forth in claim 16, wherein said injectioncannula is 31 or 32 gauge.
 18. An administering apparatus with a dosagedisplay, comprising a casing, a reservoir for a fluid product, a drivendevice which acts on the product, a dosing means for selecting a productdosage to be delivered comprising a dosage scale comprising a number ofdosage marks axially spaced from each other, and a drive device coupledto the driven device for driving the driven device, wherein the casingis transparent at least in an area overlapping the dosage scale, andwherein the drive device forms an indicator relative to the dosage scaleto indicate the initial position of the drive device.
 19. The apparatusaccording to claim 18, wherein the drive device performs a deliverystroke in a drive direction and can only be moved relative to the drivendevice opposite the drive direction, by a path length which correspondsto a remaining dosage in the reservoir.